This invention relates generally to surgical access introducers, and more particularly to access introducers for performing minimally invasive surgical procedures such as endoscopic and laparoscopic procedures.
Trocars or introducers having a cannula for use as a conduit for endoscopic or laparoscopic instruments in the performance of surgical procedures within bodily cavities such as the abdomen are well known in the art. However, the prior art devices heretofore available have a number of deficiencies. First, known devices are adapted to be used with 5 mm, 10 mm, or 12 mm instruments, but none to date have been adapted for instruments as small as 2.2 mm or less in cross-section. Furthermore, most prior art devices typically have complex, semi or fully automatic anchoring devices for retaining the introducer in position within the bodily cavity. These devices may comprise inflatable balloons or mushroom hinges, and typically employ spring biased mechanisms which react to either a manual or automatic triggering stimulus to deploy the anchoring device. Such devices are complex and expensive to manufacture.
An additional problem inherent in prior art introducer devices which employ associated anchoring mechanisms is that the cannula requires a thicker wall structure in order to support the anchoring mechanism and associated forces which are generated through the anchoring process. These thicker wall structures result in the requirement of additional forces on the part of the physician to insert the introducer. Introducer devices are typically inserted into the desired bodily cavity using an entry device, such as a Veress needle or other type of puncturing implement, which has a sharp needle for insertion into the tissue barrier surrounding the bodily cavity. The Veress needle is placed through the lumen of the introducer device so that its needle end extends distally past the distal end of the introducer in order to initiate the insertion procedure. However, since the needle end of the Veress needle is substantially narrower than the cross-sectional area of the introducer, particularly with the thickened cannula walls necessary to support the anchoring device, a substantial insertion force is required to insert the introducer device through the incision created by the Veress needle, and tearing of the tissue surrounding the insertion site often occurs.
Yet another problem encountered in prior art introducer devices concerns the routine implementation of a relatively large support disk, which is designed to slide axially along the exterior surface of the introducer cannula after insertion into the bodily cavity, until it rests against the outside surface of the tissue barrier, at the insertion site, in order to provide support for the introducer and associated surgical instruments during the ensuing surgical procedure and to prevent inadvertent extension of the access cannula into the bodily cavity. Unfortunately, it is often desirable to visually access the insertion site during the surgical procedure, in order to ascertain whether the site is torn or bleeding, or whether there is excessive leakage of fluids from the bodily cavity, and the support disk obscures this visual access.